The invention relates to microphone arrangements, especially, but not exclusively, for telephones.
There is increasing concern that, in telephony, the replacement of analogue switches by digital switches and the replacement of non-linear carbon microphones by linear microphones have resulted in a degradation in service quality. This is believed to be due to the lack of background noise suppression by the recently-adopted linear microphones. This increased noise creates listening problems not only at the far end but also at the near end, where the sidetone suppression is degraded by the poor impedance matching of digital switches.
It has been proposed to use a pressure gradient type of linear microphone to improve background noise suppression because it discriminates in favour of sounds originating close by. In particular, its response is proportional to the inverse square of the distance of the source. However, such a microphone is not entirely satisfactory for a telephone handset because it is very directive. A user would have to orient the handset carefully to avoid nulls or low sensitivity.
An object of the present invention is to mitigate this problem.